Creatinine is a product of protein metabolism in the body, and low creatinine levels during pregnancy are most often considered to be due to a lack of protein-based nutrients consumed by pregnant women. During pregnancy, pregnant women need to consume more protein-based nutrients to maintain their own physical health and the healthy development of their babies. Some pregnant women may suffer from the effects of early pregnancy reaction or due to the enlarged uterus pressing on the gastrointestinal tract during late pregnancy, which affects the normal digestion and absorption function of the gastrointestinal tract, and the insufficient intake of eggs, milk, fish, meat and other high-quality protein diets, making the protein nutrient deficiency in the body, which may cause the creatinine concentration to drop. Severe cases can cause protein malnutrition, resulting in physical developmental disorders, developmental delays in babies, and reduced resistance to disease in pregnant women.